How much HP does a Kei car have?

Kei cars typically top out at around 63 PS (about 62 horsepower) under Japanese regulations, coming from a 660cc engine with a strict power cap that keeps performance modest. This cap helps define the Kei class's balance of affordability, fuel efficiency, and urban practicality.

Regulatory horsepower cap

To understand how much horsepower a Kei car can produce, it helps to know the official limits that govern the class in Japan. The rules set a maximum engine displacement and a ceiling on power output, which together pin Kei cars to a light, efficient performance profile.

Key specifications that determine the Kei car horsepower ceiling:

• Engine displacement: up to 660 cubic centimeters (cc)


• Maximum power output: 47 kW (63 PS)

These limits mean that conventional Kei cars—those powered by internal combustion engines—are designed to deliver performance in the low-to-mid range by today’s standards, emphasizing city-friendly acceleration and excellent fuel economy.

Real-world performance

In everyday driving, most Kei cars deliver roughly 50–60 hp, with the exact figure depending on the model, turbocharging, and tuning. Turbocharged variants exist that push toward the regulatory ceiling, while non-turbo variants typically sit closer to the lower end of the range. Electric Kei cars (EVs) follow the same size and weight constraints but use electric motors, which can deliver different peak torque characteristics and horsepower figures from the same chassis class.

Electric Kei cars

Electric Kei cars are designed to fit the same kei dimensions, but their power is measured in kilowatts and may vary by model. While they still aim for city-friendly performance and efficiency, the peak motor output can differ from gasoline Kei cars depending on the motor and battery configuration. Always check the specifications for a given model year to understand its actual horsepower or kilowatt rating.

Examples and context

Popular Kei models in the market typically advertise outputs that align with the 63 PS cap or hover just below it, especially in sportier or turbocharged variants. For instance, several turbocharged Kei cars reach the upper end of the class’s power range, while most non-turbo models provide comfortable urban performance without crossing the cap.

Summary

Kei cars are purposefully limited in horsepower to maintain their compact size, light weight, and affordability. The official ceiling is 47 kW (63 PS), from a 660cc engine. In practice, most Kei cars produce about 50–60 hp, delivering practical city driving performance and strong fuel efficiency. Electric Kei models follow the same class constraints but use electric motors, offering different power delivery profiles while still conforming to the kei-size framework.

How much horsepower does a kei car have?

63 hp
Both use a single electric motor with a maximum output of 47 kW (63 hp; 64 PS).

How much horsepower does a kei truck engine have?

Kei trucks have a maximum horsepower limit of 64 horsepower (PS) due to Japanese regulations for vehicles in this class. The exact horsepower for specific models can vary, often ranging from around 40 to 50 horsepower, though some turbocharged versions can reach up to 64 horsepower. 
You can watch this video to learn about the Kei car regulations, including the horsepower limit: 56sThe Fast Lane TruckYouTube · Jan 14, 2025

• Maximum limit: The official maximum is 64 horsepower (47 kW), a "gentleman's agreement" that has been in place since 1998. 
• Typical range: Many standard, non-turbocharged kei trucks have between 40 and 50 horsepower, depending on the make and model. For example, a Subaru Sambar can produce between 44 and 53 horsepower, while some Daihatsu Hijets might be in the 38-44 hp range. 
• Turbocharged versions: Some models, especially those from the 1990s, came with a factory supercharger (turbo) which could boost them to the 64 horsepower limit. 
• Engine size: The horsepower limit is tied to the engine displacement, which cannot exceed 660cc (0.67 liters). 

This video provides a review of the Suzuki Kei Truck and discusses its horsepower: 1mUpper James ToyotaYouTube · Jul 5, 2025

Are Kei cars legal in the US?

Kei cars older than 25 years are legal for road use in the US, as they are exempt from federal safety and emissions standards, though state and local laws vary widely. Newer kei cars are not street legal at the federal level but can be imported for off-road or private property use. Legality for road use depends on the state, and even if a state has a general exemption, individual states may have specific restrictions or refusal to register certain models.
 
Older kei cars (25+ years old)

• Federal exemption: Vehicles 25 years or older can be imported into the US without meeting federal safety or emissions standards. 
• State-level legality: Once imported, a kei car's road legality depends on the state where it is registered. Some states allow them for full road use, while others may have special registration for off-road or low-speed use, or ban them entirely. 
• Examples of states that allow registration: A number of states have laws that allow 25+ year-old kei cars to be registered for road use, but you must check your local laws as they can change. 

Newer kei cars

• Not street legal: Newer kei cars do not meet the federal safety standards required for US roads and cannot be registered for public road use.
• Private property use: They can be imported for use on private property only, such as farms or private industrial sites. 

Important considerations

• Check local and state laws: The most crucial step is to verify your specific state's laws, as registration requirements and restrictions can vary significantly. 
• Emissions and safety: Even in states that allow older models, there can be confusion or varying interpretations of local emissions and safety regulations. 
• Registration: Be aware that even if a state allows them, there may be other requirements to jump through to title and register the vehicle. 

Is 5000 hp possible in a car?

Yes, a car can have 5,000 horsepower, and there are both concept and custom-built examples. The Devel Sixteen is a concept car with a claimed 5,007-horsepower V16 engine, while custom drag racing cars also achieve this level of power through extreme engine configurations. 
Examples of 5,000+ horsepower cars

• Devel Sixteen: This UAE-based concept car is built around a 12.3-liter V16 engine with four turbochargers that has been dyno-tested at over 5,000 horsepower. 
• Custom drag cars: In the world of extreme drag racing, builders have created custom cars that exceed 5,000 horsepower. For example, a Proline Hemi engine built for a project car named "Eagle" is a 5,000-horsepower engine, and a 1969 Camaro has been documented as making over 5,000 horsepower for drag racing. 

Challenges and considerations

• Engine and powertrain: To achieve this level of power, engineers use massive engines with numerous cylinders and multiple turbochargers to force in more air. 
• Chassis and suspension: The car's chassis, suspension, and tires must be significantly reinforced to handle the immense stress and torque generated by such a powerful engine. 
• Fuel: These cars typically require specialized, high-octane race fuel and other advanced tuning to operate correctly. 
• Street legality: Many of these vehicles are not street-legal due to their extreme nature and are built for racing or exhibition purposes only.